If I go in, and there's another fella in there I'd use the urinal farthest from him, but not if it's the childrens one.
If it's packed, then I'd go to the first available one. Look down, and hope I don't seize up.
Seizing up is when nothing comes out, and you stand there with no weeing sound, like a muppet, and looking pretty homo.
Even if I go in with someone I know, I might say a couple words, but with strangers nothing is said.
Also, to show that I haven't seized up, I start splashing all over the urinal, so that it's loud and everyone can here.
I then wash my hands.